Certification Method
An Optical Microscopy and Image Analysis method was used to certify our Monodisperse Standards against a NIST calibrated stage micrometer.

The method was based on guidelines developed at the French National Physical Laboratory (CNRS) for the certification of European particle size standards in the BCR Certified Reference Material project.In the certification process, a half an hour period was allowed for equilibration of both optics and electronics before calibration of the system using the NIST reference.

5 separate analyses on different days were performed by different technicians to determine the measurement uncertainty at the peak. In percentage terms, this rarely exceeds +/-2.5%.